TW201643172A - Preparation of high conductivity copper films - Google Patents

Abstract

A copper precursor composition contains: a first copper complex of an imine or a first cyclic amine coordinated to a first copper precursor compound; and, a second copper complex of a primary amine or a second cyclic amine coordinated to a second copper precursor compound. A copper precursor composition contains a copper complex of an imine coordinated to a copper precursor compound. The copper precursor composition is thermally degradable at a temperature lower than a comparable composition containing only primary amine copper complexes under otherwise the same conditions to produce a metallic copper film having a resistivity of about 200 [mu][Omega],cm or less. Inks containing the copper precursor composition and a solvent may be deposited on a substrate and sintered to produce a metallic copper film. The substrate with the film thereon is useful in electronic devices.

Description

Preparation of highly conductive copper film

This invention relates to methods and compositions for making highly conductive copper films on substrates, particularly for flexible circuits.

The manufacture of low cost electronic devices relies on the ability to print circuits on inexpensive plastic substrates using additional printing techniques. Manufacturing conductive inks that can be used in low-cost printing technologies such as inkjet, screen, elastic or gravure, while providing the necessary electrical and mechanical properties, remains a challenge in printable electronic materials due to the smaller size And higher density will lead to new topics. Although sheet-like silver conductive inks meet many of today's conditions, and silver nanoparticle inks have excellent electrical properties and are therefore forward-looking, cost-effective copper-based inks, although performing well in electromigration, have The options are limited, and this problem plagues the silver circuit and becomes even more important as it introduces higher density designs.

The pyrolysis of anhydrous copper (II) formate (Cu(OOCH) ₂ ) is known to occur at about 200 ° C, while Cu ⁰ , H ₂ and CO ₂ are produced in a stepwise cation reduction reaction with copper (I) as an intermediate. . Copper coordination compounds are attracting ink materials because they are inexpensive, easy to prepare and handle, compatible with a variety of different printing methods, and have excellent electrical properties. For example, copper (II) formate coordinated to an alkylamine such as hexylamine and octylamine will be converted to metallic copper by pyrolysis under relatively mild conditions to provide a copper circuit having a resistance value as low as 5.0 micro ohms. Unfortunately, the commonly used sintering conditions result in the deformation of polyethylene terephthalate (PET), especially when subjected to tension, thus limiting its use. Further, in the roll-to-roll method, the sintering time of about 30 minutes causes it to lose its attraction. PET is an inexpensive substrate suitable for making low cost electronic materials by screen or inkjet printing.

Copper formate coordinated to the pyridine derivative has been used as a precursor for metallic copper (US 6,770,122). Copper formate coordinated to a piperidine derivative has been used as a precursor for metallic copper (US 2014/0349017). However, these documents do not show the use of a printable ink that can be sintered at low temperatures, less time, and ambient pressure compatible with PET to produce a low resistance copper film.

A copper precursor composition provided by the present specification comprises: a first copper complex comprising an imine or a first cyclic amine coordinated to a first copper precursor compound; and a second copper complex comprising Positioning to a second amine or second cyclic amine of the second copper precursor compound, the copper precursor composition being lower than the comparable composition comprising only the second copper complex under the same conditions The temperature is thermally degraded to produce a metallic copper film having a resistance of about 200 micro ohms or less.

Further provided is a copper precursor composition comprising a copper complex comprising an imine coordinated to a copper precursor compound.

Further provided is a copper ink comprising the above copper precursor composition and a solvent.

A substrate is further provided comprising a copper ink line deposited on the surface of the substrate.

Further provided is a method of manufacturing a metallic copper film, comprising: sinking copper ink The ink is deposited on the surface of the substrate and sintered to produce a metallic copper film.

Other features will be described or disclosed in the following detailed description. It is to be understood that each of the features described herein can be used in combination with any one or more of the other described features, and that each feature does not necessarily depend on the presence of another feature, unless any one of skill in the art is apparent.

For ease of understanding, the preferred embodiment will be described by way of example and with reference to the accompanying drawings, wherein: FIG. 1A depicts the resistance (micro ohm ̇ cm) as a function of the weight fraction of 3ButPy versus EtHex after heating to 170 °C. Picture.

Figure 1B depicts a graph showing the resistance (micro ohm ̇ cm) of a copper film composed of EtHex (black diamond) and 60% 3ButPy (white square) as a function of sintering temperature.

Fig. 2 is a graph showing the electric resistance (micro ohm ̇ cm) of a copper film composed of each DiMetPip ink and sintered at 110 ° C and 150 ° C.

Figure 3A depicts a graph of the TGA of copper (II) formate coordinated to each imine.

Figure 3B depicts a DTGA of copper (II) formate coordinated to each imine.

In one embodiment, the copper precursor composition comprises: a first copper complex comprising an imine or a first cyclic amine coordinated to the first copper precursor compound; and a second copper complex comprising Positioned to a second amine or a second cyclic amine of the second copper precursor compound. Preferably, the first copper complex comprises: two cyclic amines, which may be the same or different, preferably the same; the two imines may be the same or different, preferably the same; or a cyclic amine and An imine. Preferably, the second copper complex comprises: two primary amines, which may be the same or different, preferably the same; the two cyclic amines may be the same or different, preferably the same; Or a primary amine and a cyclic amine. The first and second copper complexes are different complexes.

In another embodiment, the copper precursor composition comprises a copper complex comprising an imine coordinated to a copper precursor compound.

Cyclic amines contain a cyclic structure that contains one or more nitrogen atoms in the ring. The ring may contain, for example, 1, 2 or 3 nitrogen atoms. At least any nitrogen atom should be available for coordination to copper. Preferably, the ring has 1 or 2 nitrogen atoms, more preferably 1 nitrogen atom. The ring also contains at least one carbon atom, preferably from 1 to 7 carbon atoms. The ring may also contain one or more heteroatoms such as O or S. Preferably, the ring contains only nitrogen and carbon atoms. Preferably, the cyclic amine comprises a 4-membered ring, a 5-membered ring, a 6-membered ring, a 7-membered ring or an 8-membered ring. 5-membered ring, 6-membered ring and 7-membered ring are particularly good. The 6-member ring is the best. The cyclic amine can comprise one or more ring structures, wherein the ring structure is fused or non-fused. At least either of the ring structures contains a nitrogen atom, although the other ring structure may or may not contain a nitrogen atom. The ring structure can be aromatic or non-aromatic.

The ring may be unsubstituted or substituted with one or more substituents. Substituents may include, for example, hydrogen, halogen, hydroxy, decyl, carbonyl, substituted carbonyl, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, and substituted alkynyl. Substituted substituents may be substituted by one or more substituents listed above. Preferably, the substituent comprises an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group or a substituted alkynyl group. In certain embodiments, a substituent on the ring is preferred because the substituent on the ring can assist the first copper complex to be more compatible with the second copper complex. In this regard, the substituent on the ring of the first copper complex preferably has similar solubility characteristics as the organic group constituting the moiety of the primary or cyclic amine of the second copper complex. The compatibility of the first and second copper complexes reduces the tendency of one or the other copper complex to crystallize.

The cyclic amine preferably contains from 1 to 30 carbon atoms and from 1 to 3 nitrogen atoms. More preferably, the cyclic amine contains 4 to 20 carbon atoms. The cyclic amine further contains one nitrogen atom, which is located in the ring structure and can be used for copper coordinated to the first copper precursor compound. Preferably, the ring structure in the cyclic amine contains from 4 to 6 carbon atoms. Any substituent on the ring structure preferably contains from 1 to 8 carbon atoms each. Preferably, the ring structure contains from 1 to 3 substituents other than hydrogen. It is preferred that the cyclic amine has one ring structure.

Some examples of nitrogen-containing ring structures include unsubstituted or substituted aziridines, diazines, azetidine, dihydroindole, dipyridinium, pyrrolidine, pyrrole, imidazolidinium, pyrazole, imidazole, pyrazole Porphyrin, pyrazole, triazole, tetrazole, piperidine, pyridine, tetrahydropyran, pyran, piperazine, pyrazine, pyrimidine, pyridazine, morphine, triazine, nitrogen heterocycle, hydrazine, high Piperazine, diazonium, azacyclooctane, aziridine tetraene and structural isomers thereof. Pyridine and piperidine are particularly preferred.

The substituent other than hydrogen on the ring structure preferably contains a C _1-8 alkyl group, a C _2-8 alkenyl group and a C _2-8 alkynyl group. A C _1-8 alkyl group is more preferred. a C _1-8 alkyl group includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, t-butyl, pentyl, hexyl, heptyl, octyl and Its isomers.

Alkyl-substituted pyridines and piperidines are specifically mentioned here. One or more alkyl groups may be substituted on the pyridine or piperidine ring. Preferably, there are from 1 to 3 alkyl substituents, more preferably 1 or 2 alkyl substituents. The alkyl substituent is preferably a C _1-8 alkyl group.

The imine contains at least one nitrogen atom coordinated to copper. The imine of the formula (I) is preferably: Wherein R _1, R ₂ and R ₃ are the same or different and may be H, alkyl (e.g. C _1-8 alkyl), alkenyl (e.g., C _2-8 alkenyl), alkynyl group (e.g., C _{2- 8} alkynyl), cycloalkyl (eg C _3-8 cycloalkyl), aryl (eg C _6-14 aryl), alkaryl (eg C _7-20 alkaryl), aralkyl (eg C _7-20 aralkyl), OH, O-alkyl (eg OC _1-8 alkyl), O-aralkyl (eg OC _7-20 aralkyl), O-alkylaryl (eg OC _{7 -20} alkaryl), CO ₂ -alkyl (eg CO ₂ -(C _1-8 alkyl)), SO ₂ -alkyl (eg SO ₂ -(C _1-8 alkyl)) or SO-alkyl ( For example, SO-(C _1-8 alkyl)) or R ₁ and R ₂ combine to form a ring (for example, a C ₃ -C ₈ ring), provided that at least one of R ₁ , R ₂ and R ₃ is not H.

In R ₁ , R ₂ and R ₃ , the alkyl group includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, t-butyl, pentyl, hexyl, Heptyl, octyl and their isomers. Aryl groups include, for example, phenyl, naphthyl and anthracenyl. Cycloalkyl groups include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl. The aralkyl group includes, for example, (C _6-14 aryl)(C _1-4 alkyl) _x wherein x is 1-3. Alkaryl groups include, for example, (C _1-4 alkyl) (C _6-14 aryl).

A cyclic imine is specifically proposed here. Some examples of cyclic imines are unsubstituted and substituted azacyclopropenes, hydrazines and dihydropyrroles.

A primary amine of the formula R-NH ₂ is preferred wherein R is an organic group. R is preferably a C ₃ - C ₂₀ organic group, more preferably a C ₆ - C ₁₂ organic group. The organic group is preferably an unsubstituted alkyl group, an unsubstituted alkenyl group or an unsubstituted alkynyl group, more preferably an unsubstituted alkyl group. The unsubstituted alkyl, alkenyl or alkynyl group is preferably straight or branched. Some specific examples of primary amines include hexylamine, octylamine, and ethylhexylamine.

The copper precursor compound comprises copper ions, preferably copper (II) ions, and one or more ligands coordinated to the copper ions. The one or more ligands can be a ligand that can be removed from the copper ions by thermal action. Ligands suitable for copper precursor compounds are known in the related art. Some examples of suitable ligands include organic or inorganic ligands bonded to copper by atoms other than carbon atoms (e.g., oxygen, nitrogen, sulfur, halogen). Combinations comprising at least any of the above may be used. Inorganic ligands include, for example, nitrates, carbonates, halides, perchlorates, hydroxides, and tetrafluoroborates. Organic ligands include, for example, carboxylates, sulfonates, and decylamines. Preferably, two ligands are coordinated to the copper precursor compound. The two ligands may be the same or different, preferably the same. The one or more ligands preferably comprise a carboxylate anion such as formate, acetate, oxalate, propionate, butyrate, ethylhexanoate, neodecanoate, pentafluoropropionate, citrate, Glycolate, benzoate, trifluoroacetate, phenylacetate, acetylacetonate and hexafluoroacetic acid-pyruvate groups. C _1-12 alkanoates are particularly preferred. Formate is the best. The first and second copper precursor compounds may be the same or different, preferably the same.

The copper complex can be produced by reacting a cyclic amine, an imine or a primary amine, and a copper precursor compound can be added as the case may be. The copper precursor compound may comprise one or more coordinating leaving groups (eg, water, ammonia, etc.) which are substituted by a cyclic amine, imine or primary amine during the reaction. The reaction can be carried out in a solvent, preferably a solvent which promotes the substitution of the leaving group and does not compete with the cyclic amine, imine or primary amine for copper coordination. Such solvents are known in the related art, such as acetonitrile, dimethyl hydrazine (DMSO), tetrahydrofuran (THF), and the like. In some cases, the reaction can be carried out at a higher temperature to assist in the substitution of the leaving group. The amount of cyclic amine, imine or primary amine depends on the amount of molecule to be coordinated to the copper. The use of 2 molar equivalents of cyclic amine, imine or primary amine with 1 molar equivalent of copper precursor compound allows for the coordination of 2 molecules of cyclic amine, imine or primary amine to copper.

The amount of the first copper complex and the second copper complex in the copper precursor composition can be adjusted by simple experimentation to determine the properties of the first and second copper complexes. The best ratio between each other. The amount of the first copper complex relative to the second copper complex (w/w) may be between about 1 and 99%, based on the total weight of the first and second copper complexes, preferably about 5-95%, more preferably about 10-75%, or about 20-75%, or about 40-75%, or about 50-75%, or about 60-66%.

The copper ink contains a solvent and a copper precursor composition. The copper precursor composition can comprise from about 1 to 99% by weight ink based on the weight of the ink. Preferably, the copper precursor composition comprises from about 5 to 95% by weight, or from about 10 to 90% by weight, or from about 20 to 80% by weight of the ink. Consider all other compositions, including the copper precursor composition, any adhesive present, and any other composition that will typically make up the remainder of the ink. In some cases, the remainder may be from about 1 to 99% by weight based on the weight of the ink. The solvent preferably comprises from about 5 to 95% by weight, or from about 15 to 95% by weight, or from about 20 to 75% by weight, or from about 20 to 40% by weight of the ink.

The solvent can comprise an aqueous medium, an organic vehicle, or a mixture thereof. The aqueous medium contains water or water in which one or more other ingredients are dispersed. The organic vehicle may comprise an organic solvent or a mixture of organic solvents. The copper precursor composition is preferably dispersible in a solvent, more preferably soluble.

The organic solvent includes, for example, an alcohol-based solvent, a diol-based solvent, a ketone-based solvent, an ester-based solvent, an ether-based solvent, an aliphatic or alicyclic hydrocarbon-based solvent, and an aromatic hydrocarbon. Main solvent, cyano group-containing hydrocarbon solvent and other solvents.

Alcohol-based solvents include, for example, methanol, ethanol, propanol, isopropanol, 1-butanol, isobutanol, 2-butanol, tert-butanol, pentanol, isoamyl alcohol, 2-pentanol, new Pentanol, third pentanol, hexanol, 2-hexanol, heptanol, 2-heptanol, octanol, 2-ethylhexanol, 2-octanol, cyclopentanol, cyclohexanol, cycloheptanol , methylcyclopentanol, methylcyclohexanol, methylcycloheptanol, benzyl alcohol, ethylene glycol monoacetate, ethylene glycol monoethyl ether, ethylene Glycol monophenyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene Glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, 2-(2-methoxyethoxy)ethanol, 2- (N,N-dimethylamine)ethanol, 3-(N,N-dimethylamine)propanol, and the like.

The diol-based solvent includes, for example, ethylene glycol, propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentane Glycol, isoprene diol (3-methyl-1,3-butanediol), 1,2-hexanediol, 1,6-hexanediol, 3-methyl-1,5- Pentylene glycol, 1,2-octanediol, octanediol (2-ethyl-1,3-hexanediol), 2-butyl-2-ethyl-1,3-propanediol, 2.5-dimethyl Base-2.5-hexanediol 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and the like.

Ketone-based solvents include, for example, ethyl ketone, ethyl methyl ketone, methyl butyl ketone, methyl isobutyl ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone, methyl amyl Ketone, cyclohexanone, methylcyclohexanone, and the like.

Esters-based solvents include, for example, methyl formate, ethyl formate, methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate , second butyl acetate, tert-butyl acetate, pentyl acetate, isoamyl acetate, third amyl acetate, phenyl acetate, methyl propionate, Ethyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, second butyl propionate, tert-butyl propionate, pentyl propionate, isoprene Propionate, third amyl propionate, phenylpropionate, methyl 2-ethylhexanoate, ethyl 2-ethylhexanoate, propyl 2-ethylhexanoate, iso Propyl 2-ethyl hexanoate, butyl 2-ethyl hexanoate, methyl lactate, ethyl lactate, methyl methoxy propionate, methyl ethoxy propionate, Ethyl methoxy propionate, ethyl ethoxy propionate, ethylene glycol monomethyl ether acetate, diethylene glycol single Methyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monoisopropyl ether acetate, ethylene glycol monobutyl ether acetate Ester, ethylene glycol monobutyl ether acetate, ethylene glycol monoisobutyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate , propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monoisopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol single Second butyl ether acetate, propylene glycol monoisobutyl ether acetate, propylene glycol monobutyl ether acetate, butylene glycol monomethyl ether acetate, butylene glycol Monoethyl ether acetate, butylene glycol monopropyl ether acetate, butylene glycol monoisopropyl ether acetate, butylene glycol monobutyl ether acetate, butylene glycol single Second butyl ether acetate, butylene glycol monoisobutyl ether acetate, butylene glycol mono-tert-butyl ether acetate, methyl acetonitrile acetate, ethyl acetoacetic acid Ester, methyl oxobutyrate, ethyl oxobutyrate, y - lactone, o-lactone, and the like.

The ether-based solvent includes, for example, tetrahydrofuran, tetrahydropyran, morpholine, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, dibutyl ether, and Ethyl ether, dioxane, and the like.

The aliphatic or alicyclic hydrocarbon solvent includes, for example, pentane, hexane, cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, heptane, octane, decahydronaphthalene, solvent Oil brain and so on.

The aromatic hydrocarbon solvent includes, for example, benzene, toluene, ethylbenzene, xylene, trimethylbenzene (for example, mesitylene), diethylbenzene, anisole, isobutylbenzene, dihydrocarbon, tetrahydronaphthalene, chlorine. Benzene, benzyl ether, anisole, benzonitrile, propylbenzene, anisine, isobutylbenzene, indoline, tetrahydronaphthalene, anthracene, indoline, and the like.

The cyano group-containing hydrocarbon solvent includes, for example, 1-propanenitrile, 1-butyronitrile, 1-capronitrile, cyclohexanenitrile, benzonitrile, 1,3-dipropionitrile, 1,4-dibutyronitrile, 1,6 -dipentyl nitrile, 1,4-bicyclohexyl Nitrile, 1,4-dibenzonitrile, and the like.

In some cases, the solvent can be the same as the amine or imine used to form the copper complex.

Copper inks may also contain an adhesive. Adhesives are any materials that adhere the ink to the film and adhere the ink to the surface on which the ink is deposited. The adhesive preferably comprises a polymeric material, preferably an organic polymer. The adhesive dose can be expressed as the total weight of copper in the copper precursor composition. Preferably, the adhesive can be present in the ink in an amount of from 2.5 to 55% by weight based on the weight of copper in the copper precursor composition. The weight of copper in the copper precursor composition refers to the total weight of copper (without other constituents constituting the precursor composition). More preferably, the adhesive is from about 5 to about 35% by weight based on the weight of copper in the copper precursor composition. Adhesive preferably comprises an organic polymer adhesives, such as ethyl cellulose, polyvinyl pyrrolidone, epoxy, phenolic resins, phenol-formaldehyde resins (e.g. Novolac ^TM, Resole ^TM), acrylic, urethane, silicone alkoxy, styrene acrylonitrile Alcohol, polycarbonate polyolefin, polyvinyl acetal, polyester, polyurethane, polyolefin, fluoroplastic, fluoroelastomer, thermoplastic elastomer or any mixture thereof.

The substrate can be any surface on which the ink can be deposited, preferably any printable surface. Surface may comprise, for example, polyethylene terephthalate (PET), polyolefin (e.g., polyolefins filled with silicon dioxide (Teslin ^TM)), polyethylene terephthalate polyethylene naphthalate (PEN), poly dimethyl silicone siloxane (PDMS), polystyrene, polycarbonate (PC), polyphenylene Amides (e.g. Kapton ^TM), silicon film, an epoxy resin (e.g., a glass reinforced epoxy laminate), textiles (e.g. cellulose textiles) , paper, glass, metal, dielectric coating, etc. Preferably, it is a plastic substrate. It is preferably an elastic substrate. Preferred are polyethylene terephthalate, polyethylene naphthalate, polycarbonate and FR-4 (glass reinforced epoxy resin laminate), particularly preferably polyethylene terephthalate, poly Ethylene naphthalate and FR-4. Among them, polyethylene terephthalate (PET) is particularly preferred.

The ink can be deposited on the surface by any suitable method, such as screen printing, ink jet printing, flexographic printing (eg, embossing), gravure printing, offset printing, spray guns, aerosol spray printing, typesetting, spin coating, impregnation Coating, spray coating, roll coating, knife coating, bar coating, slit coating, brush coating or any other method. It is preferably a printing method. After deposition, the ink can be dried or hardened, for example by allowing the ink to dry in a surrounding environment or heating the ink for a suitable length of time to evaporate the solvent. The inks of the present invention are particularly useful for ink jet, screen, roll-to-roll, flexographic or gravure printing. The ink is suitable for roll-to-roll printing because of the lower temperatures and less sintering time.

The ink can be deposited (eg, via printing) on the surface to form an ink line on the substrate. The conductive copper film can be formed by drying and decomposing the circuitry by any suitable technique, depending on the type of substrate on which the ink circuitry is deposited. Heating the substrate will dry and sinter the line to form a conductive copper film. Sintering decomposes the copper precursor composition to form conductive copper nanoparticles. Heating is preferably performed at a temperature of about 150 ° C or less, or about 140 ° C or less, or about 135 ° C or less, or about 130 ° C or less, or about 125 ° C or less. Heating is preferably carried out at a temperature of about 90 ° C or above, or about 100 ° C or above. The ink line is preferably sintered for a time of about 30 minutes or less, or about 10 minutes or less, or about 5 minutes or less. There must be trade-offs for temperature and time, and sintering at lower temperatures usually takes a long time. The pressure can also be adjusted during sintering to change the temperature and/or time required to form the conductive copper film. The pressure is preferably about 3 atm or less, or about 2 atm or less. In an embodiment, no additional pressure is used. The type of heating device also depends on the temperature and time required for sintering. Sintering can also be performed on the substrate in an oxidizing gas environment (e.g., air) or an inert gas environment (e.g., nitrogen and/or argon). For copper inks, inert or reducing gas environments may be more Desirably, or an oxygen-depleted gas atmosphere, wherein the oxygen content is preferably about 1000 ppm or less, more preferably about 500 ppm or less.

The sintering conditions (time, temperature and pressure) required for the inks of the present invention are acceptable for roll-to-roll printing. In the prior art, the primary amine coordination copper formate complex was not suitable for roll pairs due to the relatively long sintering time. Roll printing. In addition, the sintering conditions can be accepted for printing on PET substrates, and the primary amine coordination copper formate complexes are also not suitable for this printing in the prior art. The copper precursor composition of the present invention can reduce the temperature at which the ink needs to be sintered in a short time to produce a copper film having good conductivity (low resistance).

The conductive copper film produced from the copper precursor composition preferably has the following resistance: about 150 micro ohms ̇ centimeters or less, or about 100 micro ohms ̇ centimeters or less, or even as low as 50 micro ohms ̇ centimeters or less. The conductive copper film can have a resistance value at least as good as the currently known ink while being manufactured at a lower sintering temperature in less time.

The substrate can be integrated into electronic devices such as circuits, conductive busbars (eg, photovoltaic cells), sensors, antennas (eg, RFID antennas), touch sensors, thin film transistors, and smart packages (eg, smart Drug packaging). The substrate can be used as any conductive element, such as an interconnector. The copper precursor compositions and inks thus produced can greatly reduce the size of such electronic devices.

Instance Example 1: Synthesis of Copper(II) Complex of Imidate

The copper(II)carboxylate complex is produced by the following method: 2 moles of different imines are coordinated to 1 mole equivalent of copper (II) formate.

The production method of copper (II) bis(2-ethyl-1-hexylamine)carboxylate (EtHex) is as follows: 1.0 g of copper (II) formate dihydrate was suspended in 25 ml of acetonitrile, and 1.74 ml of 2-ethyl-1-hexylamine (primary amine) was added. The solution was immediately filtered to remove unreacted copper (II) formate and the acetonitrile was removed by rotary evaporation.

The method for the preparation of copper (II) bis(3-butylpyridine)carboxylate (3ButPy) is similar to the copper (II) complex of primary amine carbamate: 1.0 g of copper (II) formate dihydrate is suspended in 25 ml of acetonitrile. And 1.57 ml of 3-butylpyridine (pyridine) was added. The solution was immediately filtered to remove unreacted copper formate and the acetonitrile was removed by rotary evaporation.

Copper (II) bis(3,5-dimethylpiperidine)carboxylate (DiMePip) was prepared by suspending 2 g of copper (II) formate dihydrate in 50 ml of acetonitrile and adding 2.809 ml of 3 , 5-dimethylpiperidine (piperidine). The solution was immediately filtered to remove unreacted copper (II) formate and the acetonitrile was removed by rotary evaporation.

The method for producing copper (II) (octyl) bis(octyl)carboxylate and copper (II) (tButPy) complex of bis(octyl)carboxylate is as described above.

Example 2: Fabrication of Copper Precursor Composition and Copper Ink

The ink of the individual copper(II) ruthenate complex is prepared by mixing 1.00 gram of the complex with 20% to 40% (grams per gram) of anisole. The mixture was homogenized by planetary mixing for 8 minutes.

The copper precursor composition comprises a copper (II) complex of primary amines and a copper (II) complex of picolinate or a copper (II) complex of piperidine. The preparation method is as follows: mixing primary copper amide (II) A complex and a copper (II) complex of picolinate or a copper (II) complex of piperidine. The mixture contains from 25% to 80% (grams per gram) of a copper (II) complex of primary amine carbamate. The ink of the copper precursor composition is produced by mixing 1.00 g of a copper precursor composition comprising the desired primary copper amide (II) complex and a copper (II) complex of pyridine or piperidine. A mixture of 20% to 40% (grams per gram) of anisole. Copper precursor composition The mixture of the substance and the anisole was uniformly mixed by planetary mixing for 8 minutes.

Example 3: Forming a copper film on a substrate

The above-described printing ink produced in a square shape on the substrate Kapton ^TM (poly Amides), a size of 1 cm x1 cm. For inks containing copper(II) picolinate complex, the ink was heated by convection using a Kar-X-Reflow 306 LF convection oven under a nitrogen atmosphere with an oxygen concentration of less than 200 ppm, wherein the square was heated at 135 ° C to 185 ° C. 5 minutes. For an ink containing a copper(II) piperidine complex, a heated plate in a nitrogen glove box is used to heat the ink through conduction in an environment having an oxygen concentration of less than 1.0 ppm, wherein the square is heated at 110 ° C to 150 ° C. minute. In contrast, an ink containing only a primary copper (II) urethane complex is heated by two methods. Heating the ink on the substrate results in the formation of a copper film on the substrate.

An ink comprising an alkylimine complex, or a mixture of an alkylimine complex and a pyridine or piperidine complex, is broken down into a film that does not have significant cracking. However, inks containing only tButPy and 3ButPy are broken down into films having significant cracking. As a result, resistance measurement for a film made of an ink containing only tButPy and 3ButPy is not reliable. Reducing the heating rate and lowering the sintering temperature does not improve the film quality of the film produced from the ink containing only tButPy and 3ButPy. An ink containing a mixture of EtHex and 3ButPy combines the good film formation characteristics of EtHex with the low decomposition temperature of 3ButPy.

Example 4: Resistance of copper lines

The resistance value of the copper film was determined on a square of 1 cm x 1 cm using a four-point detection technique. Four-point probing measurements were performed using Lucis Lab's Keithley 220 programmable current source, HP 3478A multimeter, and SP4 probe.

The best weight score for 3ButPy (eg 3ButPy/[3ButPy+EtHex]) The rate is judged at about 170 ° C to ensure that all of the different types of blends are sintered. Figure 1A shows that the sheet resistance gradually decreases as the 3ButPy fraction increases. 6.5 micro ohms The minimum resistance of ̇ cm will appear at 60% 3ButPy. In Figure IB, the resistance of a pure EtHex complex (diamond) was compared to a 60% 3 ButPy (square) blend to evaluate the effect as a function of temperature. In both cases, when the sintering temperature rises to 170 ° C, the resistance tends to be low, but when it rises to 185 ° C, the resistance value is wrong and the blackened surface is increased. Therefore, when the sintering temperature is 170 ° C or more, oxidation plays an important role in lowering the electrical characteristics of the film. At 170 ° C, the 3ButPy/EtHex ink performed better than the pure EtHex ink in resistance, and the film produced at 135 ° C had a resistance of 13.9 micro ohms per square centimeter, however, the EtHex derived line was non-conductive. When examining the behavior of the PET substrate under these sintering conditions, it has been found that the PET substrate does not show signs of distortion at up to 135 °C. Table 1 shows the substrate compatibility of EtHex and 3ButPy/EtHex inks based on the resistance values obtained by sintering at different temperatures for 5 minutes. Table 2 shows the sheet resistance of the copper film formed from EtHex and 3ButPy/EtHex inks at different sintering temperatures.

Table 3 shows sheet resistance (ohm/□) of a copper film produced from 3ButPy/EtHex inks of different compositions when sintered at 170 °C.

Figure 2 shows the copper film resistance produced by different DiMePip-containing inks as a function of temperature. Films made from pure EtHex show the lowest resistance of all ink mixtures, but do not conduct electricity when sintered at 110 °C. Although films made from pure DiMetPip show higher electrical conductivity, DiMetPip and mixtures containing more than 50% DiMetPip conduct electricity when sintered at 110 °C. Therefore, the mixture of DiMetPip and EtHex forms a conductive copper film only when sintered at a temperature lower than EtHex, and the formed copper film is superior in conductivity to a film formed only by DiMetPip. Only inks with EtHex must be sintered at a higher temperature to form a conductive copper film, and only DiMetPip produces a copper film with lower conductivity (higher resistance).

Example 5: Thermogravimetric Analysis of Copper(II) Complex of Imidate

Copper(II) imidate complex was subjected to thermogravimetric analysis (TGA) using Netzsch TG 209 F1 Iris R. The system operates in a BOC HP argon (grade 5.3) environment and the remaining oxygen is captured by a Supelco Big-Supelpure oxygen/water trap. Figure 3A and Figure 3B The mass loss (TGA) and derivative mass loss (DTGA) of the complex compound heated to 400 ° C under argon were shown. The graph shows that the decomposition temperature of the complex is reduced in the following order: first alkylamine > second alkylamine > second cyclic alkylamine > third cyclic aromatic amine.

The tButPy and 3ButPy complexes decomposed between 90-130 ° C and 75-120 ° C, respectively, however, the mass loss of the octyl and EtHex complexes spanned from 100-155 ° C. The two peaks of mass loss indicate that the copper complex is a two-stage decay to become metallic copper. Decomposition of the pyridine complex over the narrower temperature range than the alkylamine complex indicates the formation of smaller copper particles having a smaller size distribution, as a result of which can be confirmed by scanning electron microscopy (SEM) images of the copper film. tButPy results in copper particles having a smaller diameter and a narrower size distribution than particles made from EtHex (100 ± 30 nm) and octyl (240 ± 60 nm).

The pyridine and piperidine derivatives coordinated to copper (II) formate have a lower decomposition temperature than the alkylamine counterpart. The 3-butyl-pyridine ligand, which coordinates to copper (II) formate, begins to decompose at approximately 80 ° C, below the alkylamine-Cu(OOCH) ₂ derivative at 30 °C. Although copper (II) bis(3-butyl-pyridine)carboxylate has poor film formation properties, the complex compound can be combined with copper (II) bis(2-ethyl-1-hexylamine)carboxylate to produce a good film. An ink having characteristics, a short sintering time, and a low decomposition temperature. An ink incorporating pyridine-Cu(OOCH) ₂ or piperidine-Cu(OOCH) ₂ and alkylamine-Cu(OOCH) ₂ produces copper with high conductivity (low resistance) when manufactured in a lower temperature process. membrane.

References: The overall content of each reference is incorporated in this reference.

CN 1071182. Hu G. (1993) Heat Sensitive Variable Colour Mimeograph. April 21, 2993.

GB 1443099. Toyo Ink Mfg. Co. (1976) Phthalocyanine Pigment Composition. July 21, 1076.

EP 0335237. BASF AG. (1989) Inks for Ink-jet Printing. October 4, 1989.

US 5,980,622. Byers GW. (1999) Magenta Dyes for Ink-jet Inks. November 9, 1999.

US 6,521,032. Lehmann et al. (2003) Magenta Inks Comprising Copper Complex Azo Dyes Based on 1-Naohthol-di- or tri-Sulfonic Acids. February 18, 2003.

US 6,770,122. Du Pont. (2004) Copper Deposition Using Copper Formate Complexes. September 29, 2004.

US 7,473,307. Song et al. (2009) Electroless Copper Plating Solution, Method of Producing the Same and Electro Less Copper Plating Method. January 6, 2009.

US 8,262,894. Xu et al. High Speed Copper Plating Bath. September 11, 2012.

US 2008/178761. Tomotake et al. (2008) Method of Forming Metal Pattern, and Metal Salt Mixture. July 31, 2008.

US 2014/349017. Abe T. (2014) Copper Film-forming Composition, and Method for Producing Cooper Film by Using the Composition. November 27, 2014.

WO 2004/035691. Nippon Kayaku KK. (2004) Phthalocyanine Compound for Ink-jet Printing, Water-soluble Green Ink Composition Containing Such Compound and Coloring Substance Using Such Composition. September 1, 2004.

WO 2006/093398. Inktec Co., Ltd. (2006) Conductive Inks and Manufacturing Method Thereof. September 8, 2006.

JPH 10279868. Canon KK. (1998) Ink Containing Organometallic Compound, Electrode, Electron-emitting Element and Production of Image Former. October 20, 1998.

JP 2000-136333. Dainichiseika Color Chem. (2000) Colored Composition for Color Filter, Production of Color Filter, and Color Filter Produced. May 16, 2000.

JP 2004-162110. Mitsubishi Paper Mills Ltd. (2004) Copper/Amine Composition. June 10, 2004.

JP 2009-256218. Toray Industries. (2009) Copper Precursor Composition, and Method of Preparing Copper Film Using the Same. November 5, 2009.

Araki T, Sugahara T, Jiu J, Nagao S, Nogi M, Koga H, Uchida H, Shinozaki K, Suganuma K. (2013) Cu Salt Ink Formulation for Printed Electronics using Photonic Sintering. Langmuir. 29(35), 11192- 11197.

Choi YH, Lee J, Kim SJ, Yeon DH, Byun Y. (2012) Highly conductive polymer-decorated Cu electrode films printed on glass substrates with novel precursor-based inks and pastes. J. Mater. Chem. 22, 3624-3631 .

Farraj Y, Grouchko M, Magdassi S. (2015) Self-reduction of a copper complex MOD ink for inkjet printing conductive patterns on plastics. Chem. Comm. 51, 1587-1590.

Hwang J, Kim S, Ayag KR, Kim H. (2014) Ink Electrode Material Using Copper Formate-Bicarbonate Complex for Printed Electronics. Bull. Korean Chem. Soc. 35(1), 147-150.

Kim I, Kim Y, Woo K, Ryu E-H, Yon K-Y, Cao G, Moon J. (2013) Synthesis of oxidation-resistant core-shell copper nanoparticles. RSC Adv. 3, 15169-15177.

Lyons AM, Nakahara S, Marcus MA, Pearce EM, Waszczak JV. (1991) Preparation of copper poly(2-vinylpyridine) nanocomposites. J. Phys Chem. 95(3), 1098-1105.

Shin DH, Woo S, Yem H, Cha M, Cho S, Kang M, Jeong S, Kim Y, Kang K, Piao Y. (2014) A Self-Reducible and Alcohol-Soluble Copper-Based Metal-Organic Decomposition Ink for Printed Electronics. ACS Appl. Mater. Interfaces. 6(5), 3312-3319.

Yabuki A, Arriffin N, Yanase M. (2011) Low-temperature synthesis of copper conductive film by thermal decomposition of copper-amine compositiones. Thin Solid Films. 519, 6530-6533.

Yabuki A, Tanaka S. (2012) Electrically conductive copper film prepared at low temperature by thermal decomposition of copper amine complexes with various amines. Mater. Res. Bull. 47(12), 4107-4111.

Yabuki A, Tachibana Y, Fathona IW. (2014) Synthesis of copper conductive film by low-temperature thermal decomposition of copper-aminediol complexes under an air atmosphere. Mater. Chem. & Phys. 148(1-2), 299-304 .

After reviewing the above description, new features will be apparent to those skilled in the relevant art. However, it should be understood that the scope of the patent application should not be limited to the implementation, but should The broadest interpretation is given in terms of the overall scope of the patent application and the description.

Claims (17)

A copper precursor composition comprising: a first copper complex comprising an imine or a first cyclic amine coordinated to a first copper precursor compound; and a second copper complex comprising coordination to a second copper precursor compound or a second cyclic amine, the copper precursor composition being heatable at a lower temperature than the comparable composition comprising only the second copper complex under the same conditions Degradation, a metal copper film having a resistance of about 200 micro ohms or less is produced. The composition of claim 1, wherein the first copper complex comprises two imines or two cyclic amines. The composition of claim 1 or 2, wherein the first copper complex comprises a cyclic amine and the cyclic amine comprises a 6-membered ring. The composition of claim 3, wherein the 6-membered ring is pyridine or piperidine. The composition of any one of claims 1 to 4, wherein the cyclic amine is substituted with one or more C _1-8 alkyl groups. The composition of any one of claims 1 to 5, wherein the first copper precursor compound comprises a copper (II) ion and one or more carboxylate anions coordinated to the copper (II) ion. The composition of claim 6, wherein the one or more carboxylate anions are two formate groups. The composition of any one of claims 1 to 7, wherein the second copper complex comprises two primary amines. The composition of any one of claims 1 to 8, wherein the primary amine has the formula R-NH ₂ wherein R is a C ₆ -C ₁₂ unsubstituted alkyl group. The composition of any one of claims 1 to 9, wherein the primary amine is octylamine or ethylhexylamine. The composition of any one of claims 1 to 10, wherein the second copper precursor compound comprises a copper (II) ion and one or more carboxylate anions coordinated to the copper (II) ion. The composition of claim 11, wherein the one or more carboxylate anions are two formate groups. The composition of any one of claims 1 to 12, wherein the first copper complex is present in the composition in an amount of from about 20 to about 75% (w/w), with the first and second copper The total weight of the compound is based on the basis. A copper ink comprising the copper precursor composition as defined in any one of claims 1 to 13 and a solvent. A substrate comprising a trace amount of copper ink as claimed in claim 14 deposited on a surface of a substrate. A method of producing a metallic copper film, comprising: depositing a copper ink as defined in claim 14 on a surface of a substrate, and sintering the ink to produce a metallic copper film. The method of claim 16, wherein the temperature is 125 ° C or below.